If a GT3 can have a Roll Bar, why can't I?
 

As I slowly make my way down the slippery slope, I have come to the point of contemplating a roll bar for my 80% street / 20% DE 87 Carrera. The gent that died at Summit Point this past summer (in a S2000 - RIP) was a family friend of my wife, so you can bet I am hearing all about safety on the track. (Latest speculation to the cause of the accident was a shattered rear rotor at high speed on a straight - why don't they publicize this stuff so we can learn from it?)

So the only way I am going to get back out there is with a 5/6 point harness, proper seat, and a Hans device. I don't have the garage space or money for a dedicated track car, so I am left with modifying the Carrera. However, I want to keep the 80/20 mix. So I started researching roll bars in street cars...

I came across this thread that discussed whether overall safety is increased or decreased on the street with a roll bar (potential head injuries vs roll over protection):

http://forums.pelicanparts.com/showthread.php?t=367299&highlight=roll+bar+safe+st reet

At last count, the poll was at 65% for safer w/ the bar, 35% not safer (without helmet and other stuff). Some replies to the thread mentioned that there was no way a roll bar was safe without a helmet due to your head's tendency to move anywhere from 2-3' from its normal position during a collision.

So I started thinking - aren't new GT3s sold with roll bars that are legal for the street (including older GT3s, 993 RS, and 964 RS)? In our litigious American society, how would this be allowed if they were so unsafe? I understand that the seats are hard backed, but how are they different then what I can buy for my car on the aftermarket? Here are some pics:


http://forums.pelicanparts.com/uploa...1235095656.jpg
http://forums.pelicanparts.com/uploa...1235095703.jpg



In addition, if you look at Boxsters and Z3s, their factory roll hoops are pretty close to driver's heads as well.


http://forums.pelicanparts.com/uploa...1235095834.jpg
http://forums.pelicanparts.com/uploa...1235095862.jpg
http://forums.pelicanparts.com/uploa...1235095887.jpg


So what do you think? If these OEM setups are safe enough for the street (and unhelemted heads), can I have a setup like this with a reasonable amount of risk?

http://forums.pelicanparts.com/uploa...1235096085.jpg

Tony,

I actually think that for US import they cannot have a roll bar in the new GT3, GT2, etc. I could be wrong on that, but if I recall correctly the 2 differences between US and Euro GT3RS's are that 1) the US version losses the roll bar, and 2) fixed back seats were replaced with sport seats. Porsche has now designed a sport seat that folds so that takes care of #2, but I do believe #1 is still a hurdle that the new owner must install after the purchase.

For added safety in a street car I would consider some high density foam designed specifically for this job.

US market cars are not available with a roll bar. One can be purchased from the Tequipment catalog and installed by a dealer though.

The idea of a "street/de" car is a compromise, especially as more components that used to be "for racers only" have become either 1) more readily available to the DE crowd or 2) We pretend to be much safer than our predecessors.

As for the accident at SP.. guess what, at 120mph if your rear rotor explodes, you could be "sol" with or without a rollbar, imho. To protect yourself 100% would require a Hans, harnesses, race containment seat and full cage.

If you ever look at a crash in slow motion it is amazing how much your head/neck and whole body move. On the street its very possible for your head to flop around a smack the rollbar... or the steering wheel.. or the drivers window.. of the winshield.

My apologies - I wasn't saying that anything would save you if your rear brake rotor exploded going real fast and you totally lost control, I was just illustrating what was the speculated reason for the accident and how the lack of information about what really happens in accidents like these could potentially make us a safer DE community. But since it did not happen on a public road, there is no requirement to make anything public (NTSB)...


OK so take out the roll bar in the US GT3 (I guess Europeans accept the risk). What about the roll hoops on the Boxsters/Z3s? They are pretty close to your head. Has anyone ever heard of a person in a Boxster hitting their head on the roll hoop?

Oh and yes I agree about the SFI padding - although many say no amount of padding will protect your un-helmeted head.

My argument is with a strong, fixed back seat (much like GT3 seats), the risk of hitting your head on a bar slightly behind the B-pillar is - what, acceptable? I realize this is the key; what amount of risk are you willing to accept. My point is that I believe others driving these cars are accepting a similar amount of risk, so I guess it makes me feel better.

I am also short (5'6") so I am little bit farther forward than most.

If safety is paramount, you should also consider a fuel cell, a 3 layer suit and a fire suppression system... you see, this is a compromise. If you really want to be safe on the track and street, in my opinion, you should not be driving a 22 year old car. With a 22 year old car, you are much less safe on the street, period, compared to a newer car. Get a new BMW/Porsche and you can do both much safer.

Compromise - agreed. The Boxster/GT3 thing just popped in my head last night after I was reading that thread. I wanted to see what you thought...

Newer cars are safer, but I love my Carrera. Yet another compromise.

My 1983 Jeep left the factory with a roll bar covered with flimsy nerf material. It's dangerous that way, but not as dangerous as the car would be without the hoop.

My advice would be to cover everything within 24" of your head with high-density SFI padding. Then drive with the knowledge that your car is now safer in the event of a lateral hit or a rollover.

As a footnote, you'll start looking at the hard edges of the roofline, A-pillar and B-pillar in a whole new way (they're not padded at all). Cars and cages are both made out of steel, and steel hurts when you hit it.

My wife hit her head--hard, bloody, required several stitches--on our Boxster's roll hoop when she was rear-ended by a moron in a Ford Excursion doing 40-50 while trying to deal with kids in the back seat. (Also broke eight ribs.) Don't know what that proves or doesn't prove other than the fact that the Boxster's roll hoops are covered with material that is not cosmetic but is a very high-density shock-absorbent material.

In the same vein, in terms of overall safety I think protecting against a rear-ender--by far the single most common kind of accident in this day of multiple driver distractions--is vastly more important than protecting against a serious rollover in a 911. Consider what you and your seat will do when slammed from behind, with a roll bar's lateral member a foot or less behind your spine. No amount of padding will help when you hit that--or it hits you, whatever you want to call it. My roll bar (street/track '83 SC) has a serious seatback-support unit as part of it. To me, that's a whole lot more important than wondering what will happen in the event of a Daytona 500-type end-over-end crash.

I agree about rear-end impacts being a bigger threat on public roads (although freeway rollovers are not an uncommon occurrence; I've personally seen a lot of them). I added an inch of SFI padding to my Brey-Krause seatback brace. I was little concerned that the foam rubber that comes stock on the thing was really only there to keep it from scratching the back of the race bucket. My spine deserves all the energy absorption I can engineer.

I did exactly that--padded my brace with SFI, which I had welded up to conform laterally to my seat, didn't like the small Brey-Krause unit--but I wonder, do 911s go flat-topped in rollovers? Maybe so, but the ones I've seen seem to end up with a reasonably intact cabin area. Anyway, we don't have crazed freeways in New York. Just the LIE.

Well, great minds think alike.

And since you've done some time as a volunteer EMT, you might see the value of the statistics I just dug up with a search. Every year, rollover accidents account for an astonishing 33% of all auto accident fatalities, even though rollovers occur in only only 3-4% of accidents. 11,000 people die on American roads every year from rollover accidents and about 24,000 suffer permanent disabilities as a result of rollovers.

Also surprising: Federal roof-safety standards have not been updated in 30-odd years, and I think the last attempt to require stronger roofs (proposed under Bush) failed. If that's the case, then a 2009 911 doesn't have to be any safer in a rollover than my '72.

Now, it might be that the mumbers I got are wrong (here's a link to the PDF with the NHTSA report). And it could be that those fatality numbers wouldn't change significantly if all cars came equipped with cages (although a lot of race sanctioning organizations would probably beg to differ). I know that seatbelt use would cut the fatality numbers significantly.

And it might be that the 911 is more sturdy than most when it lands on its roof. But...

http://www.wreckedexotics.com/911/911_091502_007.jpg

This guy might have a roll bar in his car, or it might be an indication of the strength of the 911 greenhouse:

http://www.wreckedexotics.com/911/911_112202_003.jpg
http://www.wreckedexotics.com/911/911_112202_001.jpg


33% of all auto fatalities is pretty significant. I'd love to see the people who believe that a cage or roll bar makes a street car less safe come up with some numbers on cage-induced injuries that might balance out that 11,000 annual fatality number.

Steve I hope your wife is/was ok.

Thanks for those statistics Jack. There was a pic somewhere recently (either here or on Rennlist) that showed a Carrera after a roll over where the A-pillar was completely cut in half. Made me wonder about those roll over standard you mentioned. If you guys have some time, I would love to see pics of your seat back braces and overall setups. Thanks again.

Well, maybe I'll leave mine in. I was planning on taking it out this spring, since I'm done DE'ing...though then I'll have to use it as a single-occupant vehicle (not a big deal, since I only drive it for fun anyway), since the right seat has no back brace.

This GT3 rolled 5 or 6 times at a very high rate of speed at our PCA DE event. You can see it faired well and both driver and passenger walked, away wearing only street belts.

http://forums.pelicanparts.com/uploa...1235150676.jpg

I've never seen a street roll-over until I moved to LA - go figure (big top heavy car + over-reaction = roll over). I used to think how could that ever happen on a highway. Obviously its much better to just hit someone that swerve beyond your cars capability. Very sad and unnerving seeing these.

Anyway - I would be worried on the street (no helmet) with a full roll cage. A behind the seat roll-bar, not as much. Your only likely to hit it in a rear-ended, and as previously mentioned, this can be negated slightly by a good seat or seat bracing. You head moves everywhere regardless of the collision direction.

You need to think about worst case scenarios, and I think you will be better with a rear roll-bar in those instances. I would definitely pad it with very high density material. Regular foam doesn't do anything at these forces. Styrofoam is what you would want. Just look at any helmet - its basically a plastic cover styrofoam bucket. It may hurt if you hit at lower forces, but at high ones, it will absorb enough while hopefully keeping your head from the metal bar.

Styrofoam is definitely _not_ what you want. You want the high-density, microcellular material that is sold by raceware providers for exactly this purpose--padding rollbars/cages. Styrofoam will kill you. Helmets are different.

Perhaps according to US standards (sadly), but I can't believe German or EU standards would be that lax. I think that's why your photo illustration and JMatta's speak volumes...the newer cars are just safer.

While I'm here I'll add my opinion, but emphasize that it's truly only an opinion and I'm no expert. I would think if you're going to be flinging your 911 near or to it's max on a semi regular basis, you'd want at least the rear cage so you can go full harness and HANS. I, too, would risk whatever damage might occur on the street (where I never drive 10/10th or even 9/10ths) to have the added safety on the track.

I actually wouldn't take the photos as evidence of much of anything. A collapsed roof means the car landed upside down with some force. An intact roof can simply mean there wasn't a lot of force transferred/absorbed when the car rolled onto its roof. The big factors are going to be the amount of energy the car is 'carrying' -- the speed it's going when it starts to tumble -- and whether it lands on the roof from some height, or if it's lucky enough to just roll onto the roof.

That said, the newer Porsches might have more strength, and TUV standards might be stricter than the long-out-of-date US ones. I don't know.

It's also interesting when you look at the rollover fatality percentage state by state. Stephan mentioned that there isn't all that much opportunity to go fast for long stretches in his corner of the world. Washington DC has only 10% of its fatalities from rollovers -- where Montana has them cause 67% of its traffic-accident deaths.

Excellent point. And as we all know, the strangest things can happen in a real world accident.

But I still stick with my belief / observation that the newer cars are stronger. :)